Hello,
I'm using a DWA-140 rev. B2 wireless adapter, connected to a DIR-615 wireless router (hw rev D3, fw rev 4.13) on a Windows 7 32 bit desktop into a small apartment. The DWA-140 is the only device connected to the router.
I am using WPA2-AES encryption. The adapter successfully connects at 300 Mbps to the router. The problem is that when I'm starting a heavy download, the link speed drops at around 100 Mbps, sometimes even around 40 - 50 Mbps. Also the signal strength drops from 4 bars to 3 bars. Is this a normal behavior? I tried using the latest driver from Ralink for the chipset used in DWA-140 adapter, but it happens the same.
I also tried with a Toshiba laptop with built-in N WI-FI. It connected at 150 Mbps, but the link speed did not drop at all under heavy download. Also the signal strength was at 5 bars in the whole apartment.
So I think that the problem might be at the DWA-140 adapter. Do you have any suggestions how I could fix this problem or should I buy another adapter?